Photofrin, a photosensitizing drug used in photodynamic therapy (PDT) for treating certain cancers, is derived from hematoporphyrin, a compound naturally found in human blood, specifically in the red blood cells.

Here's why:

* Hematopophyrin extraction: Photofrin is created through a complex process that starts with extracting hematoporphyrin from human blood. This process involves a series of purification steps.

* No animal involvement: The production of Photofrin does not involve using blood from any other animal, including pigs.

* Ethical considerations: Using animal blood for medication would raise ethical concerns and would be a complex process with potential issues in terms of disease transmission.

It's possible you might have heard about other medications or therapies involving animal products, but Photofrin specifically is not made from pig blood.